Recurrent precursor-B acute lymphoblastic leukemia presenting as a cervical malignancy

A 59 year old woman with a history of acute lymphoblastic leukemia in remission presented with right flank pain. An abdominal ultrasound showed mild to moderate right hydronephrosis due to obstruction, and computed tomography scan showed a bulky mass near the cervix, concerning for cervical or uterine malignancy. A Papanicolaou smear was suspicious for malignancy, and immunocytochemical stains were positive for terminal deoxynucleotidyl transferase (TdT) and cluster of differentiation (CD)-10, focally positive for CD34 and CD79a, and negative for CD3, CD20, and paired box protein-5 (PAX-5). Cervical biopsies showed an infiltrating population of cells with immunophenotype similar to the cells on cervical cytology. The cytologic and histologic workup was compatible with infiltration of the uterine cervix by recurrent precursor-B acute lymphoblastic leukemia. A bone marrow biopsy showed normocellular marrow without evidence of tumor or infiltrative disease. Complete blood count and peripheral blood smear showed no evidence of leukemic involvement. Acute lymphoblastic leukemia diagnosed on cervical Pap smear has been very rarely reported. The majority of cases of hematologic malignancy involving the uterine cervix present with vaginal bleeding. To our knowledge, only three cases of recurrent precursor-B acute lymphoblastic leukemia in the uterine cervix have been reported, two of which occurred in pediatric patients. One pediatric patient presented with vomiting and abdominal pain, and was found to have hydronephrosis on imaging. This is perhaps the first case of precursor-B acute lymphoblastic leukemia diagnosed on cervical cytology in an adult patient with hydronephrosis and without vaginal bleeding.